How to build the perfect sandcastle?

How to build the perfect sandcastle is a question that many children and adults consider during the summer. The answer to the question, as put forward by scientists, is water.

That water is the key to the most robust sandcastle may seem strange but water serves to build small bridges between grains of sand, sticking them together and increasing the strength of the structure.

So far, perhaps, nothing new. What a research team have done, however, is to calculate exactly how much water produces the strongest sandcastle. The outcome, according to The Economist, is that 1% water needs to be added to dry sand to create the best structure. The water serves as a type of ‘glue’ for the sand molecules, making them stronger by altering the surface tension of each grain of sand.

The finding has come from a science team based at the University of Amsterdam’s Institute of Physics, led by Daniel Bonn. For the research, according to the LA Times, the scientists looked at the stability of wet sand columns in terms of height and weight. By controlling the water content, the researchers built sandcastles up to five metres tall (over sixteen feet).